Molecular cloning and characterization of caprine <Emphasis Type="Italic">calpastatin</Emphasis> gene

Calpastatin (CAST) is an important gene for meat quality traits in livestock and poultry. The cDNA of caprine CAST gene was amplified for the first time using RACE-PCR. Results showed the full-length cDNA of caprine CAST gene (Accession no. GU944861) was 2435 base pair (bp) and contained a 2187 bp open reading frame encoding a protein with 728 amino acid residues. Bioinformatic analysis indicated that caprine CAST cDNA was 89.8–95.4, 83.5–92.2, 72.8–81.8 and 69.8–73.5% identical to sheep, cattle, pig and human CAST cDNA. It was predicted that caprine CAST contained four conserved domains with 42 serine phosphorylation loci, 18 threonine phosphorylation loci, 1 tyrosine phosphorylation locus and 5 specific PKC phosphorylation loci. This work provided an important experimental basis for further research on the function of CAST in goat.     

Analysis of clinically relevant substrates of CYP2B6 enzyme by computational methods

Mounting evidence thus far indicates that human cytochrome P450 2B6 (CYP2B6), an enzyme expressed at a relatively low level functionally, is primarily responsible for the metabolism of several clinically relevant drugs, including propofol, efavirenz, bupropion, mephobarbital, and the propofol analog 2,6-di-sec-butyl phenol. We used molecular dynamics and molecular docking methods to predict such interactions and to compare with experimentally measured metabolisms. Insight II and Discover Studio 2.5 were used to carry out the docking of these substrates into CYP2B6 to explore the critical residues and interaction energies of the complexes. Phe297, Glu301, Thr302 and Val367 were identified as major drug-binding residues, which is consistent with previous data on site-directed mutagenesis, crystallography structure, and from modeling and docking studies. In addition, our docking results suggest that nonpolar amino acid clusters and heme also participate in binding to mediate drug oxidative metabolism. The binding modes of the five clinically relevant substrates mentioned above for metabolism on CYP2B6 are presented.     

眼皮肤白化病患者酪氨酸酶基因突变的研究

目的：对临床诊断为眼皮肤白化病（OCA）患者的酪氨酸酶（TYR）基因进行突变筛查,了解我国大陆OCA患者TYR基因突变类型,探讨基因突变对人TYR蛋白结构和功能的影响。方法：应用PCR技术,扩增患者及其父母的TYR基因外显子、外显子-内含子交界区及启动子区;以DNA序列测定技术,进行突变筛查与鉴定;利用生物信息学方法,对突变引起蛋白结构和功能的改变进行预测与分析。结果：在15名患者的30个TYR等位基因内,查明11种突变;其中错义突变5种（W400L、R299H、E294K、R77Q和K142M）,无义突变3种（R116X、R278X和G295X）,插入突变2种（929insC和232insGGG）,剪切位点突变1种（IVS1-3 C〉G）;对4个突变W400L、R299H、929insC、232insGGG的生物信息学分析显示,突变的致病性与蛋白结构和功能的改变相关。结论：W400L占本研究所检出全部OCA1突变等位基因的30．0％（9／30）,可能为中国大陆人群中较常见的TYR基因突变类型;应用生物信息学分析方法对TYR基因突变的致病性做出一些合理可能的解释是可行的。     

Molecular genetic mapping of a high-lysine mutant gene (<Emphasis Type="Italic">opaque-16</Emphasis>) and the double recessive effect with <Emphasis Type="Italic">opaque-2</Emphasis> in maize

The lysin content in maize endosperm protein is considered to be one of the most important traits for determining the nutritional quality of food and feed. Improving the protein quality of the maize kernel depends principally on finding a mutant with a higher lysine content. Two high-lysine mutant lines with opaque endosperm, QCL3024 and QCL3021, were isolated from a self-cross population derived from Robertsons Mutator stocks. The gene controlling this mutation is temporarily termed opaque-16 (o16). In order to illuminate the genetic locus and effect of the o16 gene, two F_2:3 populations, one developed from a cross between QCL3024 and QCL3010 (a wild type line) and another from a cross between Qi205 (opaque-2 line) and QCL3021, were created, and F₃ seeds from the F₂ plants in the two populations were evaluated for lysine content. The distributions of lysine content and tests for their normality indicate that the lysine content in the two populations is regulated by the major gene of o16 and genes of o2 and o16, respectively. Based on two data sets of the linkage maps of the F₂ plant marker genotypes and the lysine content of F₃ seeds originating from the two F_2:3 populations, the o16 gene was located within 5 cM, at either 3 or 2.2 cM from umc1141 in the interval between umc1121 and umc1141 on the long arm of chromosome 8, depending on the recombination rate in the two populations as determined by composite interval mapping. According to the data of the F_2:3 population constructed from the o2 and o16 lines, the double recessive mutant effect was analyzed. The average lysine content of the F₃ o2o2o16o16 families identified by the umc1066 and umc1141 markers was approximately 30% higher than that of the F₃ o2o2 and o16o16 families, respectively. The lysine content of seven F₃ families among nine F₃ double recessive mutant families showed different increments, with an average increase of some 6% compared with that of the maternal o2 line. The potential application of the o16 mutant for maize high-lysine breeding may be to combine it with the o2 mutant bearing modifier genes, thus obtaining a mutant with much higher lysine content. For the purpose of pyramiding the o16 with o2 genes, the availability of closely linked markers of the o16 and o2 loci will facilitate marker-assisted selection and greatly reduce breeding time and effort.     

广东白背飞虱早期迁入种群的虫源地分析

为了揭示广东省白背飞虱早期迁入的虫源地分布,为其精细化预测预报及源头治理提供科学依据,根据广东省雷州、肇庆、曲江、梅县4个地区的白背飞虱虫情资料,利用HYSPLIT轨迹分析平台和GIS进行早期迁入峰的轨迹分析,结果表明:(1)广东白背飞虱的迁入在早稻和晚稻上各出现一段灯诱高峰,雷州出现的灯诱高峰最早,集中在4月上旬—5月下旬,其他地区集中在5—6月;(2)曲江、肇庆的白背飞虱灯诱高峰日数明显高于雷州、梅县;(3)广东白背飞虱早期迁入的虫源地主要分布在越南中北部、老挝中南部、海南以及两广南部稻区。但其虫源地的时空分布存在季节性的差异,随着时间的推移,虫源地的分布逐渐由南向北偏移。     

Contrast observation and investigation of wheat endosperm transfer cells and nucellar projection transfer cells

In cereal seed, there are no symplastic connections between the maternal tissues and the endosperm. In order to facilitate solute transport, both the nucellar projection and its opposite endosperm epithelial cells in wheat caryopsis differentiate into transfer cells. In this paper, we did contrast observation and investigation of wheat endosperm transfer cells (ETC) and nucellar projection transfer cells (NPTC). The experimental results showed that there were some similarities and differences between ETC and NPTC. ETC and NPTC almost developed synchronously. Wall ingrowths of ETC and NPTC formed firstly in the first layer nearest to the endosperm cavity, and formed later in the inner layer further from the endosperm cavity. The mature ETC were mainly three layers and the mature NPTC were mainly four layers. Wall ingrowths of ETC were flange type and wall ingrowths of NPTC were reticulate type. NPTC were not nutrient-storing cells, but the first layer of ETC had aleurone cell features, and the second layer and third layer of ETC accumulated starch granules and protein bodies.     

三种控释肥在赤红壤中的氧化亚氮排放

采用静态箱收集和对比法,研究了无作物种植条件下包膜与否对高氮、均衡及高钾3种氮磷钾配比复合肥在华南赤红壤发育的菜园土中氧化亚氮(N2O)排放情况.结果表明:肥料氮磷钾配比不同,N2O排放量差异显著,3种类型复合肥N2O累积排放量表现为均衡型≥高氮型＞高钾型;同一类型复合肥,包膜控释能显著降低N2O排放量,包膜控释高氮、均衡及高钾型复合肥N2O排放总量分别为不包膜复合肥N2O排放量的34.4％、30.5％和89.3％;与不包膜相比,复合肥包膜能降低肥料在土壤中的N2O日排放通量,滞后和削减N2O排放高峰,减少土壤氮素损失以及由N2O排放造成的全球增温潜势.     

A novel alkaline protease from wild edible mushroom Termitomyces albuminosus

A protease with a molecular mass of 30 kDa and the N-terminal sequence of GLQTNAPWGLARSS, was isolated from fresh fruiting bodies of the wild edible mushroom Termitomyces albuminosus. The purification protocol included ion exchange chromatography on DEAE-cellulose, Q-Sepharose, SP-Sepharose and FPLC-gel filtration on Superdex 75. The protein was unadsorbed on DEAE-cellulose and Q-Sepharose, but adsorbed on SP-Sepharose. The optimal pH and temperature of the purified enzyme were 10.6 and 60 °C, respectively. The enzyme was stable in the presence of 2 % (v/v) Tween 80 and 4 M urea. More than 80 % of the enzyme activity was retained in 2 % (v/v) Triton X 100, 54 % in 10 mM EDTA and 31 % in 2 % (w/v) SDS. The enzyme was strongly inhibited by phenylmethylsulfonyl fluoride (PMSF), but not inhibited by dithiothreitol (DTT), pepstatin or lima bean trypsin inhibitor suggesting that it was a serine protease but not a trypsin-like one. The protease was inhibited by Hg(2+), Cu(2+), and Fe(3+) ions. The K(m) and V(max) values of the purified enzyme for casein were 8.26 mg ? ml(-1) and 0.668 mg ? ml(-1) ? min(-1), respectively.